11- mavzu: Ishlab chiqarish xarajatlari

11.5-rasm. va grafiklarining o`zaro joylashuvi.

Rasmdan ko`rinib turibdiki, agar bo`lganda chizig`i pastga qarab tushadi va bo`lganda ham chizig`i pastga qarab kamayib boradi. Buning sababi - har bir yangi qo`shimcha birlik mahsulotni ishlab chiqarish xarajati ishlab chiqilgan mahsulotning o`rtacha va o`rtacha o`zgaruvchan xarajatidan kichik bo`lgani uchun, o`rtacha va o`rtacha o`zgaruvchan xarajatlarni kamaytiradi.

Agar va bo`lganida va chiziqlari yuqoriga qarab o`sib boradi. Bu yerda qo`shimcha ishlab chiqarilgan birlik mahsuloti xarajati va dan katta bo`lgani uchun, u ushbu o`rtacha va o`rtacha o`zgaruvchan xarajatlarini oshiradi.

YUqoridagi fikrlardan kelib chiqadiki, o`rtacha xarajat ( ) va o`rtacha o`zgaruvchan xarajat ( )lar o`zlarining minimal qiymatlarida chizig`ini kesib o`tadilar (rasmda va nuqtalar), ya’ni

bo`lganda ,

va bo`lganda .

Misol. YUqorida ko`rib o`tilgan apelsin sotuvchining xarajatlarini qaraymiz. 11.1-jadvalda sotuvchining xarajatlari tarkibi keltirilgan.

11.1-jadval.

Mahsulot	O`zgarmas	O`zgaruv-	YAlpi	CHekli	O`rtacha xarajatlar
miqdori, Q	xarajat, FC	chan xara-jat, VC	xarajat, TC	xarajat, MC	O`zgarmas, AFC	O`zgaruv- chan, AVC	Umumiy, ATC
0	50	0	50	-	-	-	-
1	50	50	100	50	50	50	100
2	50	90	140	40	25	45	70
3	50	120	170	30	17	40	57
4	50	160	210	40	13	40	53
5	50	210	260	50	10	42	52
6	50	270	320	60	8	45	53
7	50	340	390	70	7,1	49,6	55,8
8	50	420	470	80	6	53	59
9	50	510	560	90	5,5	56,5	62
10	50	610	660	100	5	61	66

Jadvalni qarasak, o`rtacha umumiy xarajatlar sotish hajmi 5 birlikka teng bo`lganda minimal 52 so`mga teng. CHekli xarajatlar sotish xajmi 2-dan 3-birlikka o`tganda minimal qiymat - 30 so`mga teng. O`rtacha o`zgarmas xarajatlar sotish hajmi oshishi bilan kamayib bormoqda.

Robert L.Sexton “Exploring economics”¹

12.3 Profit Maximization
The objective of the firm is to maximize profits. It wants to produce the amount that maximizes the difference between its total revenue and total cost.

Total revenue (TR) is the revenue that the firm receives from the sale of its products. Total revenue for a perfectly competitive firm equals the market price of the good (P) times the quantity (q) of units sold (TR = P x q).

Average revenue (AR) equals total revenue divided by the number of units sold of the product (TR/q, or P x q/q). So, in perfect competition, average revenue is equal to price of the good.

Marginal revenue (MR) is the additional revenue derived from the sale of one more unit of the good. In a perfectly competitive market, because additional units of output can be sold without reducing the market price of the product, marginal revenue is constant and equal to the market price, which is also the average revenue.

In perfect competition, then, marginal revenue, average revenue, and price are all equal: P = MR = AR.

Exhibit 1: Revenues for a Perfectly Competitive Firm

Firms will maximize profits at that output where they maximize the difference between total revenue and total costs--the output level where marginal revenue equals marginal cost.

As long as the marginal revenue derived from expanded output exceeds the marginal cost of that output, the expansion of output creates additional profits. However, expansion of output when the marginal cost of production exceeds marginal revenue will lead to losses on the additional output, decreasing profits.

The profit-maximizing level of output is where a firm’s MR = MC.

Exhibit 2: Finding the Profit-Maximizing Level of Output

Be careful not to make the mistake of focusing on profit per unit rather than total profit.

As long as producing and selling units adds more to revenues than to costs, they add to profits. However, beyond that, those units reduce profits.

Exhibit 3: Cost and Revenue Calculations for a Perfectly Competitive Firm

12.4 Short-Run Profits and Losses²

There are three easy steps to determine whether a firm is generating economic profits, economic losses, or zero economic profits:

1. Find where marginal revenues equal marginal costs and proceed straight down to the horizontal quantity axis to find q*, the profit-maximizing output level.

2. At q*, go straight up to the demand curve, then to the left (price) axis to find the market price, P*. Once you have identified P* and q*, you can find total revenue at the profit-maximizing output level, because TR = P x q.

3. The last step is to find total cost. Go straight up from q* to the short-run average total cost (SRATC) curve; this will give you the average cost per unit. If we multiply average total costs by the output level, we can find the total costs (TC = ATC x q).

If total revenue is greater than total costs at the profit-maximizing output level, the firm is generating economic profits. If total revenue is less than total costs, the firm is generating economic losses. If total revenue equals total cost, so the firm is earning zero economic profits, the firm is covering both its implicit costs and explicit costs. Economists sometimes call this zero economic profit a normal rate of return.

Exhibit 1: Short-Run Profits, Losses and Zero Economic Profits

A firm generating an economic loss faces a tough choice: Should it continue to produce or shut-down its operation? To make this decision, we need to consider average variable costs. If a firm cannot generate enough revenues to cover its variable costs, then it will have larger losses if it operates than if it shuts down (losses in that case = fixed costs). Thus, a firm will not produce at all unless the price is greater than its average variable cost.

At price levels greater than or equal to average variable costs, a firm may continue to operate in the short run even if average total costsCvariable and fixed costs--are not completely covered. Because fixed costs continue whether the firm produces or not, it is better to earn enough to cover a portion of these costs rather than earn nothing at all.

When price is less than average total costs but more than average variable costs, the firm produces in the short run, but at a loss. To shut down would make this firm worse off, because it can cover at least some of its fixed costs with the excess of revenue over its variable costs.

Exhibit 2: Short-Run Losses: Price Above AVC but Below ATC

When the price a firm is able to obtain for its product is below its average variable costs at all ranges of output, it is unable to cover even its variable costs in the short run, so since it is losing even more than the fixed costs it would lose if it shut down, it is most logical for the firm to cease operations.

Exhibit 3: Short-Run Losses: Price Below AVC

At all prices above minimum AVC, the firm produces in the short run, even if ATC is not completely covered, and at all prices below the minimum AVC the firm shuts down. Therefore the short-run supply curve of an individual competitive seller is identical with that portion of the MC curve that lies above the minimum of the AVC curve.

Exhibit 4: The Firm’s Short-Run Supply Curve

As a cost relation, the MC curve above minimum AVC shows the marginal cost of producing any given output. As a supply curve, the MC curve above minimum AVC shows the equilibrium output that the firm will supply at various prices in the short run. Beyond the point of lowest AVC, the MC of successively larger outputs are progressively greater, so the firm will supply larger amounts only at higher prices.

Exhibit 5: Deriving the Short-Run Market Supply Curve

The short-run market supply curve is the horizontal summation of the individual firms’ supply curves. Because the short run is too brief for new firms to enter the market, the market supply curve is the horizontal summation of existing firms.

Use What You’ve Learned: Reviewing the Short-Run Output Decision (Exhibit 6)

Use What You’ve Learned: Evaluating Short-Run Economic Losses (Exhibit7)

12.5 Long-Run Equilibrium³

If perfectly competitive producers are able to make economic profits, they will increase the resources that they devote to that lucrative business. As production proves profitable, there will be a supply response--the market supply curve will shift to the right over time as more firms enter the industry and existing firms expand. The impact of increasing supply, other things equal, is to reduce the equilibrium price.

As entry into the profitable industry pushes down the market price, producers will move from making a profit (P > ATC) to zero economic profits (P = ATC). In long‑run equilibrium, perfectly competitive firms make zero economic profits.

Exhibit 1: Profits Disappear with Entry

Zero economic profits is an equilibrium or stable situation because any positive economic (above‑normal) profits signal resources into the industry, beating down prices and thus revenues to the firm; economic losses signal resources to leave the activity, leading to supply reductions that lead to increased prices and higher firm revenues to the remaining firms. Only at zero economic profits is there no tendency for firms to either enter or leave the business.

Exhibit 2: Losses Disappear with Exit

The long‑run competitive equilibrium for a perfectly competitive firm can be graphically illustrated. At the equilibrium point (where MC = MR), short-run and long-run average total costs are also equal. The average total cost curves touch the marginal cost and marginal revenue (demand) curves at the equilibrium output point. Because the marginal revenue curve is also the average revenue curve, average revenues and average total costs are equal at the equilibrium point.

Exhibit 3: The Long-Run Competitive Equilibrium

The long-run equilibrium output in perfect competition occurs at the lowest point on the average total cost curve, so the equilibrium condition in the long run in perfect competition is for firms to produce at that output that minimizes per-unit total costs.

12.6 Long-Run Supply⁴

The shape of the long-run supply curve depends on the extent to which input cost change when there is entry or exit of firms in the industry. We consider three types of cost conditions: constant-cost industries, increasing-cost industries and decreasing-cost industries.

In a constant-cost industry, the prices of inputs do not change as output is expanded. The industry does not use inputs in sufficient quantities to affect input prices.

Because the industry is one of constant costs, industry expansion does not alter firms’ cost curves, and the industry long run supply curve is horizontal. That is, once the short-run higher profits from an increase in demand has attracted entry until long run-equilibrium is again reached, the long‑run equilibrium price is at the same level that prevailed before demand increased; the only long‑run effect of the increase in demand is an increase in industry output.

Exhibit 1: Demand Increase in a Constant-Cost Industry

In an increasing-cost industry, the cost curves of the indi­vidual firms rise as the total output of the industry increases. When an industry utilizes a large portion of an input, input prices will rise when the industry uses more of that input as it expands output, which will shift firms’ cost curves upward. Once the short-run higher profits from an increase in demand has attracted entry until long run-equilibrium is again reached, producers’ MC and AC curves will be higher, so that the new long-run equilibrium is at a higher price. The long-run industry supply curve in this case has a positive slope.

Exhibit 2: Increasing-Cost Industry

Expansion in the output of an industry can lead to a reduction in input costs and shift the MC and ATC curves downward. Since a firm experiences lower costs as industry expands, the new long-run equilibrium has more output at a lower price—the long-run supply curve for a decreasing-cost industry is downward sloping (not illustrated).

As a practical matter, decreasing-cost industries are rarely encountered over a large range of output. However, some industries may operate under decreasing-cost conditions when continued growth makes possible the supply of materials or services at reduced costs

In the News: Internet Cuts Costs and Increases Competition

1^ Robert L.Sexton “Exploring economics”

12.3 Profit Maximization

2^ Robert L.Sexton “Exploring economics”

12.3 Profit Maximization

3^ Robert L.Sexton “Exploring economics”

12.3 Profit Maximization

4^ Robert L.Sexton “Exploring economics”

12.3 Profit Maximization